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BEsT AVAILABLE 001 N. TESLA. v DYNAMO ELECTRIC MACHINE.

(No Model.)

PatentedOct. 9, 1888.

HWENTOH WITNESSES:

*H ATTORNEYS.

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BESTAVAlLABLE COP NIKOL'A' TESLh, OF NEW YORK, N.. vin,

. COMPANY, OF

PATENT OFFICE.

ssslono'n re THE TESLA ELECTRIC SAME Prison.

DYNAMOv'E LECTRlC M'Acmue,

sPB'omcA-morz forming part orls'etters Patent No. 390,721, datedocto'ber s, 1888.

- Applicatioi: flied sin-n ss'isa.

To all whom it may concern: Be it known that I, Nnto'LA TFSLA, a subject of theEmperor'of Austria, fromfimiljan,

Like, border country ofAnstria-Hungary, new residing at NewjYork, in the county and State of New York, have invented certain new and useful Improvements in Electric-Generators, of which the followingis a specification, reference being had to thedrawing accompanying and forming-a; part of the same;

My present invention relates, chiefly, to the alternating-current system invented by me' and described in prior patents, notably Nos."

381,968 and 382,280, of May.1, 1888, in which the mot'crs'ortransformers', or generally the converters, are operated by a progressive shift:

ing or movement of their magnetic poles pro-1 d'nced by the co-operative action of independent magnetizing-coils through which pass alternatiug currents in proper order and direction. In my saidsystem, as I have heretofore shown, I'eiuployed a'generator of alternating currents in which there were independent induced or generating coils corresponding to the energizing-coilsof the converter, and the relations. of the generator andconverters were geuerally'snch that the speed of rotation of the magnetic poles of the converter equaled that of the armature ot the generator.

To secure the greatestlefiiciency, it is neccssary to run the "machines at a high speed, and Y this is true notonly of those generators and motors which are particularly adapted for use in my systein, but of others. The practicability of running at ,very high speeds, however, particularly in the case of large generators, is limited by mechanical conditions, in.- seeking to avoid which I have devised various plans for operating the system under efficienteondition's, although running the generatornt a comparatively low rate of speed.

My present invention consists of another way of accomplishing this result, which in certain respects presents many advantages. According to the invention, in lieu of drivin the armature of the generator at a high rate of speed, I, produce a rotation of the magnetic polcsof one element of the generatorand drive the other at. a different speed, by which simi- 5o lar results are obtained to those secured by a rapid rotation of oueof the elements.

with independent-coils or sets otcoils .T J, included, respectively, in the circuits M M. I .These energizing-coils are wound on a ring or annular field or on pole-pieces thereon, and

sauna. 2121,53. momma.)

for operating the motors or transformers cousists in this instance of a subdivided ring or annular core wound with four diametricallyoppositecoils, EE'. Within the ringis mounted a cylindrical armature-core wound longitudinally with. two independent coils, F F, the ends of which lead, respectively, to two pairsot insulated contact or collecting rings, D D' G G, on the armature-shaft.- Collecting-brushes d d g g bear. upon these rings, respectively, and convey the currents through the two independent line-circuits M M. In the mainline there may be included one or more motors or transformers, or both. If motors he used, they are constructed in accordance with my invention produce by the action of i the alternating currents passing through them aprogressive shifting of the magnetism from pole to pole. The cylindrical armature H of the motor is wound with two coils. at right angles, which form independent closed circuits.

1f transformers be employed, 1 connect one set of the-primary coils, as N N, wound on a ring or annular core, to one circuit, as M, and the other-primary-coils, N N, to the circuit M. The secondary coils K K may then be utilized 'for running groups of incandescent lamps P P. 7

With the generator I employ an exciter. This consists of two'poles, A A, of steel permanently magnetized, or of iron excited by a battery orother generator of continuous eurrents,andacylindricalarmatnre-core mounted a on ashaft, B, and'wonud with two lougitndi-p nal coils,C C. One end of each of three coils is connected to the collecting-rings b c, respect ively,while the other ends are both connected to aring, a. Collecting-brushes b c bear on the rings b 0; respectively, and conductors L L convey the currents therefrom through the coils E and E of the generator. L is a common return-wire to brush a. Two independ. ent circuits are thus formed, one iuclndin coils Got the exciter and E E of the generator,

BEST AVAILABLE COP the other coils C of the exciter and E E of the generator. It results from this that the operntionof the exciter producesa progressive movementio'f the magnetic-poles of the annular field-core of the generator, the shifting or rotary movement of said poles being synchronous with the'rotation of the'exciter-arma-- ture. Considering the operative conditionsof a system thus established, it will be'fou'nd that m when-the exciter is driven sons to energize the field of the generator the armature of the latte'ryifleft free to turn, would rotate at a speed practically the same as that of the ex citer. If under such conditions thecoils F- Fo'f the generator-armature be closed upon themseites or short-circuited, no currents-at least theoretically, will be generated in. the said armature-coils. In practice I have observed the presence of slight currents, the existence of which is attributableto'more or less pronounced fluctuations in the intensity of the magnetic poles of the generator-ring. so, it.

the armature-coils FF be plosed'through the motor, the latter will nhtbe turned as lon'gas the movement ofthe generator-armature is magnetic poles of its fleld If, on; the contra 1'y, the speed of the generator-armature be in any way chccked,so thattheshil'ting errotat-ion ol' the poles of the field becomes relatively more rapid, currents will be induced in the armature-colls. This obviously. follows from the pass-ingot the lines of i'orce across the nrmature-conductor s.- The greater; the

tively tothat of the armature the morerapidly the currents developed. in the'coils of the latter will' follow one another, and the more rapidly the motor will revolve. in response thereto, and this continues until the armaturegenerator is stopped entirely, when the motor, if properly constructed, runs at the same'speed with which the magnetic poles of the generator rotatei,

' The effective strength of the currents developed iu-the armature-coilsofi', the generator is dependent upon the strength of the currents energizing-the generator and upon the number of rotations, per unit of time of ,the mag-J netic poles of the generator; hence the speed of the motor-armature will depend in all'cases upon the relative speeds of thearmatni'e of the generator and of its'maguetic poles. .7 For example, if the poles are turned twb thousand times per uuitof time and the armature is turned eight hundred-,th motor will" turn twelve hundred times, or nearly so. Very slight difi'ercnccs of speed may be indicated by a. delicately-balanced motor.-

Let it now be assumed that power is applied to the generator-armature to turn it in a direction opposite to that in which its magnetic poles rotate. In such case the result would be similar to that produced by a generator the armature and field-magnets of which are rototed in opposite directions, and by reasonof these conditions the motor-armature will turn by checking the speed-of synchronous with that of the'exclter'or ofthe magnetic poles or conversely. It will-be understood from the above despecd 0f=rotation of the magnetic poles rela-' as by a bmke,--

operatively associatedi'in the following man- 'ata rate :of speed equal tothe sum or the speeds of the armature and magnetic poles of the generator, so that a comparatively low speed of the generator-armature will produce a high speed in the motor. 7

It will-be observed'in connection with this system that ondiminishing the resistance of the'external-circnit of the nerator-armatu re e motor or by addmultiple arc' in the iug translating devices in l sewndarycircuit orcircnits of the transformer I 'thestren'gth of the current in the armaturecircuit is greatly increased. Thisis due to the causes: first,to the great differences in the speeds of themotor andgenerator, and, secondly, to the fact that the apparatus follows the. analogy of'a transformer, for, inproportion as the resistance of the armature orsecon'dary mane is reduced; the strength oi the currents in the field-or primary circuits-of the generator is increased and the-currents in the armature augmented correspondingly. For, similar reasons the'currents in the armatureo coils of the-generator increase very rapidly a .when the speed of the armature isreduoed;

when running in the same 'directicnasthe 93. scriptlon that the generator-armature may be run in the direction ofthe shifting of the magneticpoles, but more rapidly, and thatin such case thespeed of the 'motor'willbe equal to the difierence between'the two rates.

In manyapplications'to'electricalconversion 4 and distribution this system possesses great advantages both in economy, efficiency, and, practice 'ility. v

v1 What lclaim is- I 1. The combination, withan alternating-cub rent generator having independent energizing or field and independent indn For armature coils, of an alternating-current exciton having generatihg or inducedcoi s correficit spending to and connected with the en gizing coils of the generator, as set forth.

A 2. Jinan alternating-current generator, the. combination of the elements named and eoner: ;a field-magnet wound with independent ing currents, whereby the magnetic poles produced by said coils 'will be "progressively shiftedor .moved through the field, and an armature-core; wound with independent coils,' I each "having.v terminals from i which currents aretgeliver'ed to the independent external cir-- cu: r

'3, The system of electrical distribution consisting of the combination, -with an alternat- 'ing cnrrent generatnnnhaying independent energizing-coilsandgrgrmature won lid with independentinduced c "is aqnalternatingcurrent ex'cite'r having induced corre sponding to and connected with the sum ing coils of the generator, and one or more e1 rical converters having independent inducing or energizing coils connected withthe corre-- log t cells each connected with 'a source of alternat- J'" spending armature coils of the generator, ashavingiuduoedorgeneratingcoils correspondheroin set forth. ing to and connected with the energizing-coils 4. Thecombination,wiih an alternating-cmof the generator, asset, forth.

'rent generator having a field-magnet wound NIKOLA TESLA. 5 with independent; energizing-coils and an Witnesses:

armature adapted to be rotated within the R031. F. GAYLOBD, field produced by said magnet, of an exciton PARKER. W. PAGE. 

